Cosmetic product dispenser made of barrier material

ABSTRACT

A cosmetic product dispenser, typically mascara, includes at least a container forming a reservoir for the cosmetic product, and a cap for sealed closure of the reservoir, optionally provided with an applicator for the cosmetic product. All or part of the reservoir, and at least a side wall of the reservoir, are formed by at least a thermoplastic material moulded part. The thermoplastic material includes EVOH and a second thermoplastic material selected from PA, PET, PBT, and ionomer resin.

DOMAIN OF THE INVENTION

The invention relates to the domain of packaging for cosmetic products,typically fluid to semi-solid or paste products, typically such asmascara or lipstick dispensers in the form of tubes, sticks or pencils.

STATE OF THE ART

Many mascara dispensers are already known. “Mascara” is a cosmeticproduct intended for makeup of eyelashes, and the packaging for thiscosmetic product is called a “dispenser”.

For example European application No. 96 830631.6 describes a mascaradispenser.

A mascara dispenser typically comprises an applicator provided with abrush and a receptacle forming a reservoir and containing the mascara,the applicator being able to form a sealed cap for the receptacle.

As illustrated in this European patent application, the dispenserusually comprises a fairly large number of assembled parts.

These parts are usually made of a moulded plastic material, typicallyPVC, PP or PE.

Problems that Arise

A mascara dispenser must provide sufficiently long life for the mascara,and in particular it must at all costs prevent the mascara from drying,since it must remain sufficiently fluid throughout its life so that thefinal user can apply it correctly.

Mascara can dry out for two reasons: either because the dispenser is notleak tight, the junction between the cap and the reservoir not beingsealed, or because the walls of the different parts of the dispenser arepermeable to volatile constituents of the mascara that diffuse throughthese walls, and particularly through the reservoir walls.

One standard way of measuring the diffusion rate, and thereforeevaluating the life of the mascara, is to measure the weight loss rate(WLR) of the mascara dispenser full of mascara. The life of thedispenser increases as the WLR becomes smaller.

Mascara dispenser manufacturers have already attempted to reduce the WLRby increasing the thickness of the dispenser walls, but this solution,although it may be effective for some mascara compositions, firstlyincreases material costs, and also reduces the contents of dispensers.Moreover, taking account of limitations with manufacturing processes, itis not always possible to obtain the wall thickness that would benecessary to obtain a sufficient barrier.

Moreover, mascara formulations tend to become increasingly complex andto include solvents or constituents with an increasingly wide variety ofnatures, some can be relatively volatile, so as to improve the finalperformance of the mascara. Therefore, formulation of mascaras requiresincreasingly good barrier properties by the dispenser or the materialfrom which the dispenser is made.

Therefore, the applicant has attempted to find a means of making mascaradispensers so as to simultaneously solve all problems that arise, namelythe problem of life mentioned above, the problem of high speedmanufacturing of dispensers or dispenser parts, the problem ofmanufacturing parts with relatively small dimensions and acceptablemechanical characteristics, and the dispenser cost problem, andparticularly to achieve the lowest possible material costs. Cosmeticpackagings are articles that may be deluxe articles or general consumerarticles, and consequently are controlled by simultaneous requirementsfor high quality and low production costs.

DESCRIPTION OF THE INVENTION

According to the invention, the cosmetic product dispenser, typically amascara dispenser, comprises at least one receptacle forming a reservoirfor the said cosmetic product, and a cap for sealed closure of the saidreservoir, possibly provided with an applicator for the said cosmeticproduct, all or part of the said reservoir, and at least one side wallof the said reservoir being formed by at least one moulded thermoplasticpart, and is characterised in that the said thermoplastic materialcomprises EVOH and a second thermoplastic material chosen from among PA,PET, PBT and ionomer resin.

EVOH is an ethylene vinyl alcohol copolymer, and may comprise apercentage of ethylene varying from 20 to 50% in mole % and, accordingto the invention, the said thermoplastic material may comprise an EVOHpercentage varying from 10 to 50% by weight, and preferably an EVOHpercentage varying from 20 to 40% by weight.

The applicant has observed that the means according to the invention cansolve all problems that arise, namely increasing the life of thedispensers and/or reducing the thickness of the dispenser walls.

According to a first embodiment of the invention, the said thermoplasticmaterial can form a layer of thermoplastic material composed of a mix ofEVOH and the said second thermoplastic material.

According to this embodiment of the invention, the said thermoplasticmaterial may comprise a percentage of EVOH varying from 10% to 50% byweight, and a percentage of the said second plastic material varyingfrom 90% to 50% by weight.

Preferably, the said EVOH percentage can vary from 20% to 40% by weight,and the said percentage of the said second plastic material varies from80% to 60% by weight.

In this embodiment of the invention, the said moulded part may be formedby known techniques widely used for the formation of parts, typically byextrusion-moulding or by injection-moulding, or again byextrusion-blowing or by injection-blowing in the case of concave orhollow parts.

According to a second embodiment of the invention, the saidthermoplastic material can form a multilayer material with at least twolayers of plastic material, and typically with two layers: an innerlayer being composed of a mix of EVOH and the said second thermoplasticmaterial, and an outer layer composed of the said second thermoplasticmaterial.

According to one variant of the invention, in which the said multilayermaterial may include at least three layers of plastic material andtypically three layers of thermoplastic material, a central layer iscomposed of a mix of EVOH and the said second thermoplastic material,and an inner layer and an outer layer on each side of the central layer,at least one of these layers being composed of the said secondthermoplastic material, and one of the inner or outer layers beingcomposed of a third thermoplastic material or by a second thermoplasticmaterial different from the material used in the opposite layer.

At least one face or one side of the said layer composed of the saidEVOH mix may be covered by a tie layer, so as to form a multilayermaterial typically comprising 3 to 5 layers, the said tie layer beingchosen to make one of the other two different layers adhesive, in amanner known in itself.

According to another variant of this embodiment, the said thermoplasticmaterial may form a multilayer material with three layers: one layercomposed of the said mix of EVOH and the said second thermoplasticmaterial, an adhesive tie layer and a layer typically composed of thesaid second thermoplastic material or by the said third thermoplasticmaterial.

According to the invention, the said percentage of EVOH in the said mixcan vary from 10% to 90% by weight, the said percentage of the saidsecond plastic material in the said thermoplastic material varying from80% to 60% by weight.

According to a third embodiment of the invention, the said multilayermaterial may be a material with at least five layers, three layers ofthermoplastic material and two tie layers: one layer, typically thecentral layer, being composed of an EVOH layer, and an inner layer andan outer layer on each side of the said central layer, the inner layerand outer layer composed of the said second thermoplastic materialand/or a third thermoplastic material, the said central layer and thesaid outer and inner layers comprising an adhesive tie layer betweenthem.

The said third thermoplastic material referred to in the above maytypically be chosen from among PE or PP.

In this embodiment of the invention, the said moulded part may be formedby co-extrusion of the said multilayer material, followed by moulding orblowing or co-injection.

Regardless of the embodiment of the invention, when the said secondthermoplastic material is PA, the PA may preferably be chosen from amongamorphous PAs, and totally or partially aromatic PAs.

According to the invention, at least the part(s) forming the reservoir,or the receptacle for the said cosmetic product, is (are) formed frompart(s) moulded from the material containing EVOH and the said secondthermoplastic material.

But the dispenser assembly, at least the part(s) made of a thermoplasticmaterial forming the wall, may be composed of a material comprising EVOHand the said second thermoplastic material, the said reservoir and thesaid cap forming the said moulded parts.

According to a preferred but not exclusive embodiment of the invention,the said cosmetic product may be mascara. In this case, the said cap mayinclude a brush as applicator of the said cosmetic product.

Another purpose of the invention consists of the use of a thermoplasticmaterial comprising EVOH and a second thermoplastic material chosen fromamong PA, PET, PBT, or an ionomer resin to form all or part of acosmetic product dispenser according to the invention, and moreparticularly to form a dispenser for typically fluid to semi-solidcosmetic products with a volatile constituent, typically mascara, nailvarnish, lipstick, cosmetic products in cream, stick or pencil form,intended particularly for makeup of the face or nails.

EXAMPLE EMBODIMENTS

The body and the cap of mascara dispensers are made by injectionmoulding or injection blowing when the thermoplastic material consistsof a single layer (so-called single layer material) or by co-extrusionblowing when the said thermoplastic material comprises more than onelayer (so-called multilayer material).

I—Examples of Single Layer Thermoplastic Material:

these are mixes of EVOH and the said second thermoplastic material,namely PA+EVOH, PET+EVOH, PBT+EVOH, Ionomer resin+EVOH, the content ofEVOH by weight varying from 10 to 50% by weight, the corresponding testsbeing indicated by crosses being shown in bold in the following table:Second plastic material % EVOH PA PET PBT Ionomer 10 X X X X 20 X X X X30 X X X X 40 X X X X 50 X X X X 60 X X X X 70 X X X X 80 X X X X 90 X XX X 100 X X X X

It is observed that the mechanical properties of these mixes(symbolically denoted “EVOH MIX” or “EM” for short in the remainder ofthis presentation) reduce as the content of EVOH increases, while thebarrier properties to volatile mascara products increase, such that ingeneral a good compromise between mechanical properties and barrierproperties was typically obtained for an EVOH content by weight equal tonot more than 50% (tests shown in bold characters).

II—Examples of Multilayer Thermoplastic Material:

At least one layer of “EM” was used as defined above in the table. Insome cases, and particularly when one or two SM layers of second plasticmaterials are used, it was found advantageous to use an EM layercontaining the maximum possible proportion of EVOH, while keeping theweight content by EVOH more than 50%.

When adhesive tie layers are present, they are denoted TL.

The said second plastic materials (PA, PET, PBT, ionomer) wererepresented generically by SM. When other plastic materials were used,for example PE or PP, they were called “third plastic materials” andgenerically represented by TM.

In some cases, and particularly when one or two layers SM of secondplastic materials are used, it was found advantageous to use an EM layercontaining as much EVOH as possible, while maintaining sufficient bondbetween the SE and SM layers so as to avoid the need for tie layers TL.In other cases, the EM layer was replaced by a 100% EVOH layer.

The structure of a multilayer material has been represented in thefollowing by the sequence of layers, each layer being separated from thenext layer by a “/”.

II-A Structures with two layers: EM/SM, EM typically, but notnecessarily, comprising the SM material forming the second layer, suchthat a tie layer TL is not necessary.

II-B Structures with three layers: these structures are of the EM/TL/TMtype or the SM/EM/SM type or possibly the SM/EM/SM′ type, where SM′denotes a second thermoplastic material different from SM.

II-C Structures with four layers: these structures are of theTM/TL/EM/SM type.

II-D Structures with five layers: these structures are of theTM/TL/EM/TL/TM type (where TM′ denotes a third thermoplastic materialdifferent from TM) or of the SM or TM/TL/EVOH/TL/SM or TM type, whereTM, EVOH denote a 100% EVOH layer.

I-E Structure with six layers: this is a structure with five layers towhich a layer of recycled plastic material denoted “R”, typically arecycling polyolefin, has been added, so as to reduce the final materialcost. For example the structure TM/TL/EM/TL/R/TM.

Advantages of the Invention

After carrying these tests, particularly with EVOH and amorphous PAmixes, and EVOH mixes with ionomer resin (Surlyn®), the applicantobserved that the life particularly of mascaras or nail care products ormore generally any cosmetic composition comprising a volatileconstituent, can be extended by reducing the weight loss ratio caused bydiffusion of the most volatile constituents, typically organic solventsor hydrophobic hydrocarbonated compounds with low or zero polarity, andor the wall thickness can be reduced, without needing to significantlymodify usual equipment or production rates, and also withoutsignificantly increasing the cost of manufactured products.

1. Cosmetic product dispenser, typically a mascara dispenser, comprisingat least one receptacle forming a reservoir for the said cosmeticproduct, and a cap for sealed closure of the said reservoir, possiblyprovided with an applicator for the said cosmetic product, all or partof the said reservoir, and at least one side wall of the said reservoirbeing formed by at least one moulded thermoplastic part, characterisedin that the said thermoplastic material is a mix comprising EVOH and asecond thermoplastic material chosen from among PA, PET, PBT and ionomerresin, the EVOH content by weight in the said mix being not more than50%.
 2. Dispenser according to claim 1, in which the EVOH comprises apercentage of ethylene varying from 20 to 50% in mole %.
 3. Dispenseraccording to claim 1, in which the said thermoplastic material comprisesan EVOH percentage varying from 10 to 50% by weight.
 4. Dispenseraccording to claim 1, in which the said thermoplastic material forms alayer of thermoplastic material composed of a mix of EVOH and the saidsecond thermoplastic material.
 5. Dispenser according to claim 4, inwhich the said thermoplastic material comprises a percentage of EVOHvarying from 10% to 50% by weight, and a percentage of the said secondplastic material varying from 90% to 50% by weight.
 6. Dispenseraccording to claim 5, in which the said EVOH percentage varies from 20%to 40% by weight, and the said percentage of the said second plasticmaterial varies from 80% to 60% by weight.
 7. Dispenser according toclaim 1, in which the said moulded part is formed typically byextrusion-moulding or by injection-moulding, or by extrusion-blowing ofthe said mix.
 8. Dispenser according to claim 1, in which the saidthermoplastic material forms a multilayer material with at least twolayers of plastic material, and typically with two layers consisting ofone layer, typically the inner layer, being composed of a mix of EVOHand the said second thermoplastic material, and one layer, typically theouter layer, typically composed of the said second thermoplasticmaterial.
 9. Dispenser according to claim 8, in which the saidmultilayer material includes at least three layers of plastic materialand typically three layers of plastic material, consisting of a centrallayer composed of a mix of EVOH and the said second thermoplasticmaterial, and an inner layer and an outer layer on each side of thecentral layer, at least one of these layers being composed of the saidsecond thermoplastic material, and one of the inner or outer layersbeing composed of a third thermoplastic material.
 10. Dispenseraccording to claim 8, in which the said layer composed of the said EVOHmix is covered by an adhesive tie layer on at least one face or oneside, so as to form a multilayer material typically comprising 3 to 5layers.
 11. Dispenser according to claim 8, in which the saidthermoplastic material forms a multilayer material with three layers:one layer composed of the said mix of EVOH and the said secondthermoplastic material, an adhesive tie layer and a layer typicallycomposed of the said second thermoplastic material or the said thirdthermoplastic material.
 12. Dispenser according to claim 8, in which thesaid percentage of EVOH in the said mix varies from 10% to 90% byweight, the said percentage of the said second plastic material in thesaid thermoplastic material varying from 80% to 60% by weight. 13.Dispenser according to claim 8, in which the said multilayer material isa material with five layers, three layers of plastic material and twotie layers: one layer, typically the central layer, being composed of anEVOH layer, and an inner layer and an outer layer on each side of thesaid central layer, the inner and outer layers composed of the saidsecond thermoplastic material and/or a third thermoplastic material, thesaid central layer and the said outer and inner layers comprising anadhesive tie layer between them.
 14. Dispenser according to claim 9, inwhich the said third thermoplastic material is chosen from among PE orPP.
 15. Dispenser according to claim 8, in which the moulded part isformed by co-extrusion of the said multilayer material, followed bymoulding or blowing or co-injection.
 16. Dispenser according to claim 1,in which the said second thermoplastic material is a PA preferablychosen from among amorphous PAs, and totally or partially aromatic PAs.17. Dispenser according to claim 1, in which the reservoir and the saidcap form the moulded parts.
 18. Dispenser according to claim 1, in whichthe said cosmetic product is mascara, and in which the said cap includesa brush as applicator of the said cosmetic product.
 19. The dispenser ofclaim 1, wherein a thermoplastic material comprising EVOH and a secondthermoplastic material chosen from among PA, PET, PBT, or an ionomerresin are used to form all or part of a cosmetic product dispenser. 20.The dispenser of claim 19, further comprising a typically fluid tosemi-solid cosmetic product with a volatile constituent, selected fromthe group consisting of mascara, nail varnish, lipstick, cosmeticproducts in cream, stick or pencil form, intended particularly formakeup of the face or nails.